POS0224 ENHANCED SURVEILLANCE FOR THE DETECTION OF PSORIATIC ARTHRITIS IN A UK PRIMARY CARE PSORIASIS POPULATION VERSUS USUAL CARE: RESULTS AT 24 MONTHS FROM THE THE TOTAL BURDEN OF PSORIASIS (TUDOR) RANDOMISED CONTROL TRIAL
Authors: S. Brown, L. Coates, H. Collier, C. Davies, P. Helliwell, J. Packham, M. Ransom, W. Tillett, N. Mchugh
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Delay in the diagnosis of psoriatic arthritis may be associated with poorer outcome. However, the effectiveness of strategies to enable early detection of psoriatic arthritis in a primary care population with psoriasis have not been investigated in a prospective randomised control trial. <h3>Objectives</h3> The primary objective was to determine whether early detection of undiagnosed PsA in people with psoriasis by an enhanced surveillance (ES) intervention compared to standard care (SC) improves outcome in physical function at 24 months post-registration. Secondary objectives were to compare disease activity and impact of disease between groups in those participants diagnosed with PsA. <h3>Methods</h3> A multi-centre, prospective, parallel group cluster randomised controlled trial in patients with psoriasis with no prior diagnosis of PsA was conducted. GP practices were randomised in a 1:1 allocation ratio with stratification for GP practice list size and Central Commissioning Group (CCG). A total of 133 GP practices and 2226 participants were required to achieve a target sample size for the primary analysis population of 148 participants (74 per group) with a positive diagnosis of PsA; the latter corresponding to 80% power for detecting the MCID in the primary outcome measure of 0.35 units. Participants recruited were managed according to either SC, or ES by annual rheumatological assessment. Participants with suspected inflammatory arthritis were referred, via their GP, to the local rheumatology outpatient clinic at participating hospitals for an assessment of PsA by the 'treating rheumatologist' (ES arm: at baseline, 12 and 24 months; SC arm: at 24 months). Participants diagnosed with PsA then entered the PsA-care pathway element of the trial. The primary outcome measure was the HAQ_DI at 24 months post registration in participants diagnosed with PsA. Secondary outcome measures, PASDAS and PsAID-12, were assessed over time in participants with a positive diagnosis of PsA. <h3>Results</h3> A total of 2225 participants across 135 GP practices were registered, corresponding to 1123 allocated to ES and 1102 to SC; primary analysis population consisted of 87 participants with a positive diagnosis of PsA: 64 in ES, 23 in SC (Figure one). Baseline characteristics were similar across both treatment groups. The adjusted odds ratio (OR) for achieving a HAQ-DI score of 0 at 24 months post registration in ES compared to SC was 0.64 (95% CI (0.17, 2.38)), indicating no evidence of a difference between treatment groups (p=0.5075). Moreover, the adjusted OR of achieving a higher (non-zero) HAQ-DI score at 24 months post registration in ES relative to SC arm was 1.12 (95% CI: 0.67, 1.86), again indicating no evidence of a difference between the two treatment groups (p=0.6612). There was high variability on the impact of the disease between participants over time, although the impact is generally low in this group of participants with an 'early' diagnosis of PsA. Moreover, the overall PASDAS score and component scores over time post PsA diagnosis show high variability in PsA disease activity. No adverse events were reported. <h3>Conclusion</h3> There was insufficient evidence that early diagnosis by ES and subsequent treatment improves physical function compared to SC in patients with psoriasis. Limitations included the trial being underpowered for demonstrating the pre-specified treatment effect; only 6.2% of participants recruited had a positive diagnosis of PsA, much lower than assumed (18%). The imbalance observed between treatment groups (~ 3:1 ratio (ES:SC)), is largely explained by the lower proportion of participants especially in the SC arm attending the screening visit at 24 months, and delays between referral and attending appointment with the treating clinician, all further exacerbated by the Covid-19 pandemic. Furthermore, a longer duration of follow-up may be necessary to detect differences in outcome and is planned. <h3>References</h3> Nil. <h3>Acknowledgements</h3> This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme. <h3>Disclosure of Interests</h3> None Declared.